Soft Tissue Response and IL-1β Levels Around CAD/CAM-Milled vs 3D-Printed PMMA Healing Abutments

Ali Hassan Eid Toto

Status: Active, not recruiting

Conditions: Peri-implant Soft Tissue Healing

Treatments: Device: CAD/CAM-Milled PMMA Healing Abutment; Device: 3D-Printed PMMA Healing Abutment

Study type: Interventional

Funder types: Other

Identifiers

NCT07287722

AlexandriaUali

Details and patient eligibility

About

This study looked at how the gums and tissues around dental implants heal when using two different types of temporary healing caps made of PMMA (a common dental material). These healing caps help shape the gums before placing the final crown.

There are two ways to make these caps:

1. CAD/CAM-milled (carved from a solid block)

2. 3D-printed (built layer by layer using resin) The goal was to find out which type leads to healthier gum tissue. What the Researchers Did

   • 22 dental implants in 22 patients were included.

   • Each implant received one healing cap-either milled or 3D-printed.

   • Patients were checked after 1 week, 2 weeks, and 4 weeks.

   • The team measured:

     • Gum inflammation
     • Bleeding around the implant
     • Plaque buildup
     • Pocket depth around the implant
     • Levels of an inflammatory marker called Interleukin-1β (IL-1β) in the gum fluid (higher levels mean more inflammation).
     • Surface smoothness and material quality of each type of healing cap. What the Study Found

   • Gum inflammation and bleeding were higher with 3D-printed caps, especially at week 4.

   • IL-1β levels were much higher around 3D-printed caps-showing more inflammation.

   • Both types had some increase in plaque and probing depth over time, but there was no major difference between groups.

   • The milled caps had smoother surfaces and better material quality, which may have helped reduce irritation and inflammation.

   • 3D-printed caps were rougher and had lower polymerization (more leftover monomers), which may trigger soft-tissue irritation.

What This Means

• CAD/CAM-milled PMMA healing caps appear to be safer and healthier for gum healing around dental implants.
• They may help reduce early inflammation, support better tissue health, and more predictably shape the gums during healing.

Why This Matters for Patients

• Using a smoother, better-finished healing cap may lower the risk of early gum inflammation.
• Healthier soft tissue around an implant leads to better long-term implant stability.
• This information can help dentists choose the best healing cap for optimal healing.

Study Timeframe

• The follow-up was 4 weeks, so results focus on early healing. More research is needed to know long-term differences.

Enrollment: 22 patients

Sex: All

Ages: 25 to 65 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Adults aged 25 to 65 years
• Presence of one osseointegrated dental implant placed at least 8 weeks prior to second-stage surgery
• Adequate zone of attached keratinized gingiva (> 1 mm) around the implant site
• Good general health and able to provide informed consent
• Willing and able to attend all follow-up visits (1, 2, and 4 weeks)

Exclusion criteria

• Smoking more than 20 cigarettes per day
• Presence of systemic diseases that may affect healing (e.g., autoimmune conditions, uncontrolled diabetes, immunosuppressive disorders)
• Oral inflammatory conditions or active oral infections
• History of head and neck radiation therapy or chemotherapy
• Use of corticosteroids or antibiotics within the last 3 months
• Parafunctional habits (e.g., bruxism)
• Pregnant or breastfeeding individuals
• Implants with insufficient attached gingiva or poor oral hygiene maintenance

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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22 participants in 2 patient groups

CAD/CAM-Milled PMMA Healing Abutment

Experimental group

Description:

Participants receive a customized PMMA healing abutment manufactured using CAD/CAM milling from a pre-polymerized PMMA block. The abutment is attached to the implant at second-stage surgery to guide soft-tissue healing.

Treatment:

Device: CAD/CAM-Milled PMMA Healing Abutment

3D-Printed PMMA Healing Abutment

Experimental group

Description:

Participants receive a customized PMMA healing abutment manufactured using 3D printing from a light-cured PMMA resin, followed by post-processing and UV curing. The abutment is attached to the implant at second-stage surgery.

Treatment:

Device: 3D-Printed PMMA Healing Abutment